Correlations between Structural and Electronic Properties in the Filled Skutterudite Sm_<i>y</i>(Fe_<i>x</i>Ni_1–<i>x</i>)₄Sb₁₂

A structural study of the filled skutterudite Smy(FexNi1–x)4Sb12 was performed by means of X-ray powder diffraction and μ-Raman spectroscopy with the aim to unveil the correlations between structural and electronic properties of this material and to favor the improvement of its thermoelectric performance. Samples were prepared by direct reaction of the elements at 1223 K, followed by quenching and subsequent sintering at 873 K; microstructure and composition of the obtained products were determined by SEM-EDS. The position of the boundary separating regions that obey hole- and electron-based conduction mechanisms was found by X-ray diffraction at x ≈ 0.63 and y ≈ 0.30, confirmed by measurements of room-temperature Seebeck coefficient, and discussed on the basis of crystallographic data. The presence of a discontinuity is observed in several structural and spectroscopic parameters at the p/n crossover; it is interpreted as associated with the change in the conduction mechanism. The role of the rare earth filling fraction in driving the structural response of the material is investigated too. The advantage of using X-ray diffraction and μ-Raman spectroscopy as aids in the study of electronic properties of this material is highlighted, as well as the complementarity of the two techniques.本研究针对填充方钴矿（skutterudite）型化合物Sm_y(Fe_xNi_(1–x))_4Sb_(12)开展结构表征工作，采用X射线粉末衍射（X-ray powder diffraction）与显微拉曼（μ-Raman）光谱两种表征手段，旨在揭示该材料的结构与电子性能之间的内在关联，为优化其热电性能提供支撑。样品通过单质元素直接反应法制备，反应温度为1223 K，随后经淬火处理，并于873 K下进行后续烧结；采用扫描电镜-能谱（SEM-EDS）对所得产物的微观结构与组分进行表征。通过X射线粉末衍射分析，并结合室温塞贝克系数的测量结果验证，确定了空穴导电与电子导电两种机制的分界参数约为x≈0.63、y≈0.30，并基于晶体学数据对该结果展开讨论。在p-n型导电转变点处，多项结构与光谱参数均出现不连续性，该现象被归因于导电机制的改变。此外，本研究还探讨了稀土填充率对材料结构响应的调控作用。本研究凸显了X射线粉末衍射与显微拉曼光谱在该材料电子性能研究中的辅助价值，同时证实了两种表征技术的互补性。